1. |
- Acosta, Stefan, et al.
(författare)
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Long-term testosterone stimulation induces hyperplasia in the guinea-pig prostate.
- 2004
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Ingår i: Prostate Cancer and Prostatic Diseases. - : Springer Science and Business Media LLC. - 1476-5608 .- 1365-7852. ; 7:3, s. 227-231
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Tidskriftsartikel (refereegranskat)abstract
- The relation between supraphysiologic circulating testosterone levels and prostatic diseases is unclear and difficult to study in men. Animal models may be advantageous. Based on a pilot study, testosterone enantate 50 mg (n=12) or 25 mg (n=12) was administered to guinea-pigs intramuscularly every 3 weeks, for either 7 or 14 months. The histopathology of the prostate was described. Epithelial hyperplasia was found in 14/21 animals receiving testosterone and in 7/12 very old animals, but no such changes were found in the sham or castrated animals. Testosterone stimulation seems to induce epithelial hyperplasia, but not cancer, in the guinea-pig prostate.
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2. |
- Acosta, Stefan, et al.
(författare)
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Neuroendocrine cells and nerves in the prostate of the guinea pig: effects of peripheral denervation and castration
- 2001
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Ingår i: The Prostate. - 0270-4137. ; 46:3, s. 191-199
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Neuroendocrine (NE) cells and nerves in the prostate gland are thought to play a central role in the regulation of growth, cellular differentiation and homeostasis of secretory activity. The objective of this experimental study was to describe the effects of peripheral denervation and castration on NE cells and nerves in the guinea pig prostate. METHODS: Guinea pigs underwent sham-operation, unilateral and bilateral hypogastric nerve resection, extirpation of the right anterior major pelvic ganglion (AMPG), autotransplantation of prostatic tissue and castration. Cryostat sections of prostatic tissue were examined with immunohistochemistry by using serotonin (5-HT) and chromogranin A (CgA) and various neuropeptides. RESULTS: The number of 5-HT-IR NE cells was four-fold higher than CgA-IR NE cells. The innervation pattern was uniform throughout the gland with subepithelial nerves in close proximity to NE cells. Autotransplants of prostatic tissue showed total loss of nerves, but the number and morphology of 5-HT-IR NE cells were unaltered. Extirpation of the right AMPG showed significant reduction in prostate weight, decreased density of nerve terminals in the superior part of the ipsilateral prostate, whereas the number and morphological feature of 5-HT-IR NE cells remained unaffected in the entire prostate. Castration induced atrophy of the gland with a significant reduction in weight (unpaired t-test, P < 0.001), but without effect upon 5-HT-IR NE cells. CONCLUSIONS: The guinea pig seems to be a useful animal model for studies on the role of the NE cells in the prostate. NE cells seem to be independent of innervation and androgens. It seems that other factors influence the NE cell population to a greater extent.
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3. |
- Lönnerholm, Gudmar, et al.
(författare)
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In vitro cellular drug sensitivity at diagnosis is correlated to minimal residual disease at end of induction therapy in childhood acute lymphoblastic leukemia.
- 2009
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Ingår i: Leukemia research. - Oxford : Elsevier BV. - 0145-2126 .- 1873-5835. ; 33:1, s. 46-53
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Tidskriftsartikel (refereegranskat)abstract
- Leukemic cells from 85 children with newly diagnosed precursor B-lineage ALL were tested for in vitro drug sensitivity to a panel of anti-cancer drugs. Minimal residual disease (MRD) was measured by RQ-PCR. There was a significant correlation between MRD day 29 and in vitro sensitivity to prednisolone (p<0.001) and doxorubicin (p=0.017), drugs administered during induction therapy. In patients with t(12;21) (n=20), in vitro sensitivity to doxorubicin was an independent factor for MRD <0.1% (p=0.031; R(2)=0.66). Thus, data show that in vitro drug sensitivity at diagnosis is correlated to cell kill during induction therapy as measured by MRD day 29.
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4. |
- Thörn, Ingrid, 1957-, et al.
(författare)
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Minimal residual disease assessment in childhood acute lymphoblastic leukemia : Results of a Swedish multi-centre study comparing real-time PCR and multi-colour flow cytometry
- 2009
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- In this Swedish multi-center study of early treatment response in childhood acute lymphoblastic leukemia (ALL), we evaluated the concordance between multicolour flow cytometry (FCM) and real-time quantitative polymerase chain reaction (RQ-PCR) for assessment of minimal residual disease (MRD). Multiple time points (i.e. day 15, 29, 50 and 106) were evaluated with the NOPHO (Nordic Society of Pediatric Hematology and Oncology) ALL 2000 treatment protocol as backbone. During 2002-2006, 334 children were diagnosed with ALL, where 228 had paired samples taken at any of the four time points. With the detection level of 0.1%, the concordance between RQ-PCR and FCM was 90% in the 726 paired samples analyzed. At day 29, the correlation between the methods was greater with MRD levels >0.1% (rs=0.7, p<0.001) than below (rs=0.2, p=0.024). MRD levels higher than 0.1% at day 29 was a significant predictor of higher risk of having a bone marrow relapse. This was true both for BCP ALL and T-ALL analysed with either FCM or RQ-PCR, although RQ-PCR was a better discriminator than FCM in T-ALL. However, using the NOPHO ALL 2000 protocol, our data indicate that a higher cut-off value (0.2%) should be applied in BCP ALL when using RQ-PCR as MRD method. In contrast, MRD levels ≥ 0.1%, analysed with either method late during induction therapy, was not a predictor of isolated extramedullary relapse. We therefore conclude that MRD assessment by RQ-PCR based IG/TCR rearrangement and multicolour FCM monitoring can be used as a clinical tool if the aim is to find childhood ALL cases with increased risk of having bone marrow relapses.
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5. |
- Thörnerup, Ingrid, et al.
(författare)
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Minimal residual disease assessment in childhood acute lymphoblastic leukaemia: a Swedish multi-centre study comparing real-time polymerase chain reaction and multicolour flow cytometry.
- 2011
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Ingår i: British Journal of Haematology. - : Wiley. - 0007-1048 .- 1365-2141. ; 152:6, s. 743-753
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Tidskriftsartikel (refereegranskat)abstract
- Minimal residual disease (MRD) assessment is a powerful prognostic factor for determining the risk of relapse in childhood acute lymphoblastic leukaemia (ALL). In this Swedish multi-centre study of childhood ALL diagnosed between 2002 and 2006, the MRD levels were analysed in 726 follow-up samples in 228 children using real-time quantitative polymerase chain reaction (RQ-PCR) of rearranged immunoglobulin/T-cell receptor genes and multicolour flow cytometry (FCM). Using an MRD threshold of 0·1%, which was the sensitivity level reached in all analyses, the concordance between RQ-PCR and FCM MRD values at day 29 was 84%. In B-cell precursor ALL, an MRD level of ≥0·1% at day 29 predicted a higher risk of bone marrow relapse (BMR) with both methods, although FCM was a better discriminator. However, considering the higher median MRD values achieved with RQ-PCR, a higher MRD cut-off (≥0·2%) improved the predictive capacity of RQ-PCR. In T-ALL, RQ-PCR was notably superior to FCM in predicting risk of BMR. That notwithstanding, MRD levels of ≥0·1%, detected by either method at day 29, could not predict isolated extramedullary relapse. In conclusion, the concordance between RQ-PCR and FCM was high and hence both methods are valuable clinical tools for identifying childhood ALL cases with increased risk of BMR.
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6. |
- Abrahamsson, Christoffer, et al.
(författare)
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Scatter correction of transmission near-infrared spectra by photon migration data: Quantitative analysis of solids
- 2005
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Ingår i: Applied Spectroscopy. - 1943-3530. ; 59:11, s. 1381-1387
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Tidskriftsartikel (refereegranskat)abstract
- The scope of this work is a new methodology to correct conventional near-infrared (NIR) data for scattering effects. The technique aims at measuring the absorption coefficient of the samples rather than the total attenuation measured in conventional NIR spectroscopy. The main advantage of this is that the absorption coefficient is independent of the path length of the light inside the sample and therefore independent of the scattering effects. The method is based on time-resolved spectroscopy and modeling of light transport by diffusion theory. This provides an independent measure of the scattering properties of the samples and therefore of the path length of light. This yields a clear advantage over other preprocessing techniques, where scattering effects are estimated and corrected for by using the shape of the measured spectrum only. Partial least squares (PLS) calibration models show that, by using the proposed evaluation scheme, the predictive ability is improved by 50% as compared to a model based on conventional NIR data alone. The method also makes it possible to predict the concentration of active substance in samples with other physical properties than the samples included in the calibration model.
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7. |
- Abrahamsson, Christoffer, et al.
(författare)
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Scatter correction of transmission NIR spectra by photon migration data - Quantitative analysis of solids
- 2005
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Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 1996-756X .- 0277-786X. ; 6009, s. 60090-60090
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Konferensbidrag (refereegranskat)abstract
- The scope of this presentation is a new methodology to correct conventional NIR data for scattering effects. The technique aims at measuring the absorption coefficient of the samples rather than the total attenuation, measured by conventional NIR spectroscopy. The main advantage of this is that the absorption coefficient is independent of the path length of the light inside the sample, and therefore independent of the scattering effects. The measurements in this work were made using a novel system for time-resolved measurements, based on short light continuum pulses generated in an index-guided crystal fibre and a spectrometer-equipped streak camera. The system enables spectral recordings in the wavelength range 500 - 1200 nm with a spectral resolution of 5 nm and a temporal resolution of 30 ps. The evaluation scheme is based on modeling of light transport by diffusion theory, that provides an independent measure of the scattering properties of the samples, that later is used to correct conventional NIR data. This yields a clear advantage over other pre-processing techniques, where scattering effects are estimated and corrected for by using the shape of the measured spectrum only. PLS calibration models shows that, by using the proposed evaluation scheme, the predictive ability is improved by 50% as compared to models based on conventional NIR data. The method also makes it possible to predict the concentration of active substance in samples with physical properties different from those of the samples included in the calibration model.
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8. |
- Abrahamsson, Christoffer, et al.
(författare)
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Time and wavelength resolved spectroscopy of turbid media using light continuum generated in a crystal fiber
- 2004
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Ingår i: Optics Express. - 1094-4087. ; 12:17, s. 4103-4112
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Tidskriftsartikel (refereegranskat)abstract
- We report a novel system for time-resolved diffuse remission spectral measurements, based on short light continuum pulses generated in an index-guided crystal fiber, and a spectrometer-equipped streak camera. The system enables spectral recordings of absorption and reduced scattering coefficients of turbid media in the wavelength range 500 - 1200 nm with a spectral resolution of 5 nm and a temporal resolution of 30 ps. The optical properties are calculated by fitting the solution of the diffusion equation to the time-dispersion curve at each wavelength. Example measurements are presented from an apple, a finger and a pharmaceutical tablet. (C) 2004 Optical Society of America.
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9. |
- Abrahamsson, Christoffer, et al.
(författare)
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Time-resolved NIR spectroscopy for quantitative analysis of intact pharmaceutical tablets
- 2005
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Ingår i: Analytical Chemistry. - : American Chemical Society (ACS). - 1520-6882 .- 0003-2700. ; 77:4, s. 1055-1059
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Tidskriftsartikel (refereegranskat)abstract
- Near-infrared (NIR) spectroscopy is a useful technique for quantitative measurements of intact tablets, but it suffers from limitations due to the fact that changes in the physical properties of a sample strongly affect the recorded spectrum. In this work, time-resolved transmission NIR spectroscopy was utilized to conduct quantitative measurements of intact tablets. The technique enables separation of the absorption properties of the sample from the scattering properties and can therefore handle changes of the physical parameters of the samples in a better way than conventional NIR transmission spectroscopy. The experiments were conducted using a pulsed Ti:sapphire laser coupled into a nonlinear photonic crystal fiber as light source. The light transmitted through the sample was measured by a time-resolving streak camera. A comparison of the results from the time-resolved technique with the results from conventional transmission NIR spectroscopy was made using tablets containing different concentrations of iron oxide and manufactured with different thicknesses. A PLS model made with data from the time-resolved technique predicted samples 5 times better than a PLS model made data from the conventional NIR transmission technique. Furthermore, an improvement to predict samples with physical properties outside those included in the calibration set was demonstrated.
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10. |
- Abrahamsson, Erik, 1974, et al.
(författare)
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A new reaction path for the C + NO reaction: dynamics on the 4A'' potential-energy surface.
- 2008
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Ingår i: Physical chemistry chemical physics : PCCP. - : Royal Society of Chemistry (RSC). - 1463-9076 .- 1463-9084. ; 10:30, s. 4400-9
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Tidskriftsartikel (refereegranskat)abstract
- We present a new reaction path without significant barriers for the C + NO reaction, forming ground state N((4)S) and CO. Electronic structure (CASPT2) calculations have been performed for the two lowest (4)A'' states of the CNO system. The lowest of these states shows no significant barriers against reaction in the C + NO or O + CN channels. This surface has been fitted to an analytical function using a many-body expansion. Using this surface, and the previously published (2)A' and (2)A'' surfaces [Andersson et al., Phys. Chem. Chem. Phys., 2000, 2, 613; Andersson et al., Chem. Phys., 2000, 259, 99], we have performed quasiclassical trajectory (QCT) calculations, obtaining rate coefficients for the C((3)P) + NO(X(2)Pi) --> CO(X(1)Sigma(+)) + N((4)S,(2)D) and C((3)P) + NO(X(2)Pi) --> O((3)P) + CN(X(2)Sigma(+)) reactions. We have also simulated the crossed molecular beam experiments of Naulin et al. [Chem. Phys., 1991, 153, 519] The inclusion of the (4)A'' surface in the QCT calculations gives excellent agreement with experiments. This is the first time an adiabatic pathway from C((3)P) + NO(X(2)Pi) to CO(X(1)Sigma(+))+N((4)S) has been reported.
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